1 /* Linux epoll(2) based ae.c module
2 *
3 * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * * Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * * Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * * Neither the name of Redis nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without
16 * specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31
32 #include <sys/epoll.h>
33
34 typedef struct aeApiState {
35 int epfd;
36 struct epoll_event *events;
37 } aeApiState;
38
aeApiCreate(aeEventLoop * eventLoop)39 static int aeApiCreate(aeEventLoop *eventLoop) {
40 aeApiState *state = zmalloc(sizeof(aeApiState));
41
42 if (!state) return -1;
43 state->events = zmalloc(sizeof(struct epoll_event)*eventLoop->setsize);
44 if (!state->events) {
45 zfree(state);
46 return -1;
47 }
48 state->epfd = epoll_create(1024); /* 1024 is just a hint for the kernel */
49 if (state->epfd == -1) {
50 zfree(state->events);
51 zfree(state);
52 return -1;
53 }
54 anetCloexec(state->epfd);
55 eventLoop->apidata = state;
56 return 0;
57 }
58
aeApiResize(aeEventLoop * eventLoop,int setsize)59 static int aeApiResize(aeEventLoop *eventLoop, int setsize) {
60 aeApiState *state = eventLoop->apidata;
61
62 state->events = zrealloc(state->events, sizeof(struct epoll_event)*setsize);
63 return 0;
64 }
65
aeApiFree(aeEventLoop * eventLoop)66 static void aeApiFree(aeEventLoop *eventLoop) {
67 aeApiState *state = eventLoop->apidata;
68
69 close(state->epfd);
70 zfree(state->events);
71 zfree(state);
72 }
73
aeApiAddEvent(aeEventLoop * eventLoop,int fd,int mask)74 static int aeApiAddEvent(aeEventLoop *eventLoop, int fd, int mask) {
75 aeApiState *state = eventLoop->apidata;
76 struct epoll_event ee = {0}; /* avoid valgrind warning */
77 /* If the fd was already monitored for some event, we need a MOD
78 * operation. Otherwise we need an ADD operation. */
79 int op = eventLoop->events[fd].mask == AE_NONE ?
80 EPOLL_CTL_ADD : EPOLL_CTL_MOD;
81
82 ee.events = 0;
83 mask |= eventLoop->events[fd].mask; /* Merge old events */
84 if (mask & AE_READABLE) ee.events |= EPOLLIN;
85 if (mask & AE_WRITABLE) ee.events |= EPOLLOUT;
86 ee.data.fd = fd;
87 if (epoll_ctl(state->epfd,op,fd,&ee) == -1) return -1;
88 return 0;
89 }
90
aeApiDelEvent(aeEventLoop * eventLoop,int fd,int delmask)91 static void aeApiDelEvent(aeEventLoop *eventLoop, int fd, int delmask) {
92 aeApiState *state = eventLoop->apidata;
93 struct epoll_event ee = {0}; /* avoid valgrind warning */
94 int mask = eventLoop->events[fd].mask & (~delmask);
95
96 ee.events = 0;
97 if (mask & AE_READABLE) ee.events |= EPOLLIN;
98 if (mask & AE_WRITABLE) ee.events |= EPOLLOUT;
99 ee.data.fd = fd;
100 if (mask != AE_NONE) {
101 epoll_ctl(state->epfd,EPOLL_CTL_MOD,fd,&ee);
102 } else {
103 /* Note, Kernel < 2.6.9 requires a non null event pointer even for
104 * EPOLL_CTL_DEL. */
105 epoll_ctl(state->epfd,EPOLL_CTL_DEL,fd,&ee);
106 }
107 }
108
aeApiPoll(aeEventLoop * eventLoop,struct timeval * tvp)109 static int aeApiPoll(aeEventLoop *eventLoop, struct timeval *tvp) {
110 aeApiState *state = eventLoop->apidata;
111 int retval, numevents = 0;
112
113 retval = epoll_wait(state->epfd,state->events,eventLoop->setsize,
114 tvp ? (tvp->tv_sec*1000 + (tvp->tv_usec + 999)/1000) : -1);
115 if (retval > 0) {
116 int j;
117
118 numevents = retval;
119 for (j = 0; j < numevents; j++) {
120 int mask = 0;
121 struct epoll_event *e = state->events+j;
122
123 if (e->events & EPOLLIN) mask |= AE_READABLE;
124 if (e->events & EPOLLOUT) mask |= AE_WRITABLE;
125 if (e->events & EPOLLERR) mask |= AE_WRITABLE|AE_READABLE;
126 if (e->events & EPOLLHUP) mask |= AE_WRITABLE|AE_READABLE;
127 eventLoop->fired[j].fd = e->data.fd;
128 eventLoop->fired[j].mask = mask;
129 }
130 } else if (retval == -1 && errno != EINTR) {
131 panic("aeApiPoll: epoll_wait, %s", strerror(errno));
132 }
133
134 return numevents;
135 }
136
aeApiName(void)137 static char *aeApiName(void) {
138 return "epoll";
139 }
140